Avidemux Forum

So I get the timestamp error when trying to export in copy mode some of my videos that I've edited as MP4. From what little I've read, it seems this issue is caused by VLC (which is how I trimmed videos prior to learning about Avidemux).

So what I do is export them as MKV instead. 95% of the videos that have issues exporting as MP4 export fine as MKV. But because I don't like working with non-MP4 if I can avoid it (MKVs have caused thumbnailing issues in the past), I just take that MKV and export it again as MP4. 90% of those cases export fine as well.

I don't really need to know why this workaround works (it would probably just confuse me to be honest), I just need to know that it really does work, isn't creating issues that I wouldn't notice at first glance, and won't cause problems down the road. And that's why I'm here.

Which version of AVD are you using?

The latest version (x64) is 2.8.2 r241212 (I'm assuming you're on Windows).
If you are using an older version, as per the confusing main Avidemux page download link, I would first advise to update from below.

https://www.avidemux.org/nightly/win64/

If I recall correctly, the handling of files (not just MP4) with insanely high timebase denominator like those produced by VLC is still unchanged, i. e. Avidemux replaces it with 90 kHz and fails to export in copy mode due to decode timestamp collisions. Re-encoding such streams with "Resample FPS" filter inserted into the filter chain should work at the cost of quality loss.

Anyway, r241212 or the latest VC++ nightly (the latter for those who don't need AV1 decoding support without an AV1 hw decoder) is a better choice than 2.8.1 release by far.

Quote from: sark on May 23, 2025, 09:11:26 AMWhich version of AVD are you using?

The latest version (x64) is 2.8.2 r241212 (I'm assuming you're on Windows).
If you are using an older version, as per the confusing main Avidemux page download link, I would first advise to update from below.

https://www.avidemux.org/nightly/win64/

2.8.1.

Quote from: eumagga0x2a on May 23, 2025, 04:37:31 PMIf I recall correctly, the handling of files (not just MP4) with insanely high timebase denominator like those produced by VLC is still unchanged, i. e. Avidemux replaces it with 90 kHz and fails to export in copy mode due to decode timestamp collisions. Re-encoding such streams with "Resample FPS" filter inserted into the filter chain should work at the cost of quality loss.

Anyway, r241212 or the latest VC++ nightly (the latter for those who don't need AV1 decoding support without an AV1 hw decoder) is a better choice than 2.8.1 release by far.

But if I do what I've been doing, there's no need to reencode. It just means I have to take the extra step of exporting it in MKV (copy mode), then exporting the resulting MKV in copy mode as an MP4.

Am I to take it that what I'm doing shouldn't be working the way that it does? It sounds like you're saying that videos produced by VLC will have timestamp issues regardless of export format, but that is not true in my experience. They export fine in MKV.